fix(bitcoin-wallet-snap): reveal own output scripts when signing a PSBT - #225
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jeremytsng wants to merge 3 commits into
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fix(bitcoin-wallet-snap): reveal own output scripts when signing a PSBT#225jeremytsng wants to merge 3 commits into
jeremytsng wants to merge 3 commits into
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This was referenced Aug 27, 2026
Partner PSBT templates may pay wallet scripts beyond the revealed set; BDK's lookahead lets them pass isMine while routine sync, which queries revealed scripts only, never watches them. Signing now reveals every own output script and persists the wallet before broadcast, so signed-away change is always covered by sync. The reveal runs only on the signing path: signing sits behind the user confirmation dialog, while fillPsbt and computeFee stay reveal-free so an unconfirmed request cannot advance the revealed index.
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Explanation
Second of three PRs splitting #201 per review feedback. Stacked on #224.
When the snap fills and signs a partner-supplied PSBT (bridge/swap), the template's change output pays one of our own scripts — but that script may sit beyond the revealed set. BDK's lookahead lets it pass
isMine, so we sign it, while routine sync (start_sync_with_revealed_spks) never queries it. Change we signed away can then be missing from the balance, which is the shape of both support cases behind this stack (0.09 BTC and 6.9 BTC).The rule this PR adds: if we sign it, we watch it.
BitcoinAccount.revealToScript(script): resolves the script's keychain and derivation index (derivation_of_spk) and reveals up to it (reveal_addresses_to) when it lies beyond the last revealed index. Verified against the pinned@metamask/bitcoindevkitbuild:derivation_indexreturns the last revealed index, and lookahead scripts resolve.signPsbtreveals every own output script of the PSBT after a successful signature and persists the wallet before broadcast — explicitly, sobroadcast: falseflows are covered too.fillPsbtandcomputeFee(callable without confirmation) reveal nothing, so an unconfirmed request cannot advance the revealed index; per signature the reveal distance is bounded by BDK's lookahead.References
Checklist